Fuse



Nov. 28, 1933. T. F. ViNDAL 5, ,1

FUSE

Original Filed July 19, 1929 BY 5: g t

A WITNESS ATTORNEY.

Patented Nov. 28, 1933 UNITED STATES PATENT OFFICE FUSE Thomas FrancisVindal, New York, N. L

Application July 19, 1929, Serial No. 379,467 Renewed May 29, 1933 i 1Claim. (Cl. 260-121) This invention relates to fuses and has par- 13 forengagement with coacting threads in the ticular reference to fusiblematerial for carrying electrical current.

One of the objects of the invention is to pro= vide e. removable memberfor installment in on electric circuit, which includes s fusible elementfor breaking the circuit, with e filament connested in parallel with thesold element, so that on the latter being fused the filament is therebyplaced in series in the circuit to accommodate the now of current andvisibly indicate the brook in the fuse.

Another object of the invention is the provision of e. fuse whichcontains a. fusible element having sections of different currentcepocity, so that e. filament having its terminals in shunt on sectionsof large carrying capacity moy he automatically placed in series withsold sections on the fusing of interposed section m o reduced cerrringcspocity.

it further ohject of the invention is to provide n vccuum chsmcer in a,fuse plug in which as filament is installed together with e fusihic element. Ordinarily the letter element carries the electric current, owingto the increased resist once ofiered by the filament, but on the soldele ment heinu fused the filement carries the cur rent and thereby givesforth light to indicete the breaking of the fusible element.

A still further object of the invention is the provision of u fuse ofthe sleeve described cher= octer which is simple in construction,eficient and durable for the purpose intended, and ice expensive tomanufacture.

With these and other objects in view the in vention resides in certainnovel constructions-l features, the essential charscteristics of which,hereinafter fully described, and particularly pointed out in theappended claim, ore illus= trated in the accompanying drawing, in whichzFigure l is u perspective view of my improved fuse plug.

Frc 2 is w enlarged longitudinal sectional view thereof.

M Figure 3 is e, perspective view of the fusible ele= ment and illent.

Figure 4 is o wiring diagram.

Referring particularly to the drawing on refor ence characters, thenumeral 1o clesignotes the fuse in its entirety, the body ll of whichcon structed of porcelain, hard rubber or other in= sulating material,is formed with e. central charm ber 12.

The body ii is provided with a metallic sleeve or covering, which isformed with screw usual socket member, while a. terminal 14 is alsocarried by said body. Electric current emanating from a source 15 flowsthrough wiring 16, which is connected with the screw threads of saidsocket member, and through the threads iii. A fusible element 17contacts with said threads 13 and with the terminal 14, end as theletter terminal contests with or terminal in the usual socket member,which is connected with n continuation it of the Wiring, current istransmittecl to any current consuming device such as e lump 19, therebeing e switch 20 in the circuit.

The element lt'is constructed with e pair of sections 21, 22 of likecurrent carrying cspscity While, between said sections and preferablyintegrel therewith, a reduced portion 23 of less con-ring capacity isformed. Contacting with the sections 21, 22 n parallel with the element17, and bridging the section 23, is at filament 2c of tungsten or thelike. AS the materiel of the filsmen; so is of higher resistance thanthe materiel of element 17, current flows through the letter whileilluinent remains unheated; one. as the carrying capacity of thesections 21 and 22 is greater than of the inner section 23, said lettersection fuses when the current ininressed on the circuit reaches acertain predetermined demity. After the section 23 has fused or meltedto normally break the circuit, current flows in the filament, therebyheating the letter to incom descence and giving forth lightorder tofully utilise the filament for displaying a visible end to clearlydistinguish e. fused element from others, when n number of fuses areused together, i prefer to utilize the chamber 12 es a vacuum chamber,but on inert or non-combustible gas may be used in sold chamber withoutdeparting from the invention. The body ii is therefore formed with anannular step or shoulder 25, on which, with o ring or collar 26, disc2'? of glass or other suitable trsns= porent materiel is sealed.

l t lnle hove described what i deem be the most desirable ernhodunent ofmy invention, it is obvious that more? of the detoils may be variedWithout in any way departing from the spirit of my invention, end Itherefore do not limit myself to the exact details of constructionherein set forth nor to sm th is less than the whole of my inventionlimited only by the appended cleun.

What is claimed as new is:---

A fuse plug" comprising n body member formed with end and periphereicontacts for engagement with the contacts in o fuse block, the body memtll her being hollowed out to provide a-chamber, a transparency closingthe chamber at the end remote from the center contact and having anair-tight connection with the body member to 5 preclude the entrance ofair to the chamber, a

fuse disposed interior to the chamber and connecting the center andperipheral contacts and THOMAS FRANCIS VINDAL.

